Charles Townes Interview (page: 2 / 8)

When you first formulated the idea of the maser, did you have any idea what the practical applications would be? Did you imagine compact discs or laser surgery? Did you have any idea how wide-ranging this was going to be?

Charles Townes: I recognized it was going to be important and wide-ranging. But I had no conception of the real breadth of the range. I recognized a new way of producing waves, and waves have always been important to mankind in many applications. Even amplified in a new way. And we could amplify ways we hadn't been able to amplify before. So there clearly were many new applications, but the most immediate ones that came to mind to me were in communications and radar, both things which I was quite familiar with. I saw immediately many applications there. Not in surgery though, certainly. I would say that the most exciting applications to me were in studying science. Using it to figure out more things about molecules and atoms and what was going on in scientific principles. That was what I foresaw a lot of use of it there. By no means all, and certainly not the uses of the laser.

You see, the laser, I expected to get down into the infrared, wavelengths of maybe a tenth of a millimeter or something like that. That's terribly interesting. But it wasn't down in the region of visible light waves. So I wasn't thinking about that part of it at all at that point. Even after the laser came along, there was much of it I didn't recognize, didn't think about. I recognized that light was going to be very important, many new things that could be done. For example, I think one of the most fascinating immediate applications that came up pretty quickly was the reattaching of detached retinas in the eye. Because the light can go through the lens of the eye, be focused on the back of the eye by the lens, and sort of rivet the retina back onto the back of the eye. I had never heard of a detached retina. How could I think about that kind of application? I wouldn't have known anything about it. So other people built on whatever I had done, and that's typical of science. You find one idea, and you can think of some things, but then many other people think of other things, and it just grows like a tree. Everybody adding on and there's lots of very interesting new ideas that are brought forth. I did predict a number of things, that's quite true.

You said you did realize some of the practical applications very early on. What were those?

Charles Townes: I recognized, of course, some of the practical applications, because I'd been working a great deal with communications and radar at Bell Labs, particularly during World War II. I was occupied, as most scientists were, with applications and with radar at that time. So I realized many of the applications, with a new type of amplification, which could produce and amplify waves that were shorter than we had had before, and would also produce a very noise-free amplification. A better kind of amplification than we had before. So I could see some applications in communications and radar possibly. What excited me though, were the applications in science, because I wanted to use those waves to study things -- study molecules and atoms and how they were composed and how they reacted, and solids too. That was the thing that interested me most. I had been thinking about it for a long time, if I only had such waves, the kinds of things that I could do. But there were practical applications that I recognized right away. Now many of the other practical applications that developed with time, I had no inkling of at that first point.

You also used the maser quite early for more accurate timekeeping, didn't you?

That's another thing which I was quite familiar with at that time, frequency standards and ways of producing a very constant frequency. I had worked with that some, using molecules in a different way still. And I was very familiar with that, and I recognized that we would have an oscillator then. Frequency depended primarily on the characteristics of the molecule. The characteristic of the molecule is made by nature, unchangeable in a sense. And so it would give a very constant frequency of oscillation, and hence a very good clock. And that was one of the early things we did, to test how constant it was. The first maser that worked was just great. We couldn't tell how constant it was until we built another one. And we could compare the two, and their oscillations, to see how well they kept in step. And that allowed us to show that in fact it was a very constant oscillation, an excellent clock.

How soon after Jim Gordon ran into your seminar and told you it was working, did the scientific world admit that you had really found something?

Charles Townes: I gave a talk in Washington at a meeting, the national meeting of the American Physical Society. I suppose about a month later. But of course, many of my friends then came to the lab and wanted to see it. See that it was working and so on. And many of the local people got interested in it. The word spread around some, but would say the first big contact, when I gave a talk at the American Physical Society, I gave what's called a post-deadline paper because it was too late to send in a normal paper. But I felt it was important, and the Physical Society recognized it was important and let me give a talk even though it wasn't previously scheduled. And that interested a great many people at that point.

Is it typical that ideas come to you rather suddenly, as they did with the maser, when you're not in a laboratory? Is that the way revelations often appear?

Charles Townes: Revelations are revelations. And there are times when suddenly there's a new idea that you have not realized before. And now some things you work through, you try to think about things, you write them down on paper, you figure out equations, and gradually you see from those equations something that you suspected might be there but you weren't sure, and you have proved that, yes, it's there. That's a new discovery in a way, but it's something that you felt might be there and you work it through more slowly. Then there are other times where it's just sudden. You've been toying with something, trying to think of something for quite a while, and suddenly you think you see a way to do it. There are sudden revelations like that.

Now sometimes, you think about it, and you decide that really wasn't right. It isn't going to work after all. But then there are other times when you're just almost certain that this is it. This really is the right idea. So there are many different ways in which it comes about. So far as the maser was concerned, here I was sitting in a beautiful setting of azaleas in the early morning. It was just a sort of a storybook kind of time when a revelation might occur. In the case of extension of the idea of light, to produce the laser, it was really very different. I had always had the idea, from the start, that I wanted to get to shorter and shorter waves, and I wanted to get down into the infrared. As you go from microwaves to shorter waves, you get down to about a millimeter, like that. Then you're into what people would call the "long-wavelength infrared." It's still shorter, it's infrared, then shorter and shorter, it's ordinary heat waves, and so on. Eventually, you get short enough that you're in light waves. But I wanted to get into the infrared. I felt surely it could be done. That what my original goal: to get into the infrared region, wavelengths shorter than a millimeter, let's say. But I felt the best way to try it out was to produce waves of about a centimeter, which is what we did with the maser. Maser stands for "microwave amplification by stimulated emission of radiation." That is, you stimulate the molecules to give up their energy, and thus amplify the microwaves. Microwave Amplification. But I knew the idea was applicable on down the shorter wavelengths, and that was my primary goal.

After we had worked with the maser for a while, I kept waiting and thinking, "Well, I keep thinking about how to get it down to very short waves. What's the best way?" I knew some ways that would work, but they weren't exciting ways. They would work, they wouldn't get me down to very short waves, and I kept thinking, "Well, I'll wait and see if I don't have a better idea." And I waited and I waited for about -- well, after we built the first maser, I guess I waited three years. And at that point, I said, "I just haven't had the right idea yet, but I must get down there to shorter waves. And I'll just sit down at my desk and start writing down and figuring out what's the best way I know now how to do it." And I wrote down some equations and looked at them, thinking, "How many molecules do we have to have, and how do we get them excited and enough energy to give up radiation?" And as I wrote down these equations, I suddenly realized, "Well now, wait a minute, we don't just have to get down to infrared. It's just as easy to go right on down in the visible region." As I looked at the equations, I could immediately see that, and I just never forced myself to sit down and think about it systematically. I was waiting for the great idea. But the great idea was writing down some detailed equations and thinking about those, and seeing, "Well, go right on down into the visible region," and there we had lots of techniques dealing with light and short infrared. Instead of just going down slightly below a millimeter, I could go down to a thousand times shorter than that even, just as easily. And that's where the laser came about. So I thought of ways of doing that then. That was a breakthrough, just sitting down there and saying, "Look, I've got to think about how to do this, and let's see what's the best way of doing it." A very different kind of thing. A revelation in a sense, but not with a romantic setting.

What first sparked your interest in science? When did you first decide to become a scientist?

Charles Townes: What interested me about science really is our universe. And just everything about the universe. I like to understand and see. I lived on a small farm when I was young, and would go out and find things, and collect insects and look at trees and look at the stars. And just looking around at nature was what really interested me first, and that was from a very early age.

Charles Townes: They were not pushing me in any particular direction. They themselves, I would say, they were interested in natural history and they encouraged me. They didn't object to my having insects in the house, for example, crawling around. So they were helpful, but they weren't encouraging me in any one particular direction.

What did you find so stimulating about the idea of being a research scientist?

Charles Townes: I like to try to understand things. You know, that's a very great human drive, curiosity. What is this world here for? What's it doing? What makes it work? How does it work? It's like solving puzzles. But they're interesting puzzles, in that once you find out something new, in science, then it's the possession of everybody. And everybody else then builds on that. So you're not just solving some puzzle that everybody else has solved once, and then you tear it apart and it has to be solved again. In science, you solve a puzzle, understand something new, and it's exhilarating, and it's everybody's property then, which everybody can use. So it's a permanent contribution.

Charles Townes: Yes, that's right. I have a brother who is an entomologist. And I used to do a lot of collections with him. And even after I was grown, I did some collecting in various foreign countries to add to his collection.

We've heard that your father was big on encyclopedias.

Charles Townes: Yes, that's quite right. My father, and my mother too, but particularly my father. But, a question would come up, and we would talk or argue about what the facts were. My father would always pull out the encyclopedia and really look and see if one could establish what really was the facts, rather than just leaving it open or a matter for opinion. We had several sets of encyclopedia. Whenever a new one came out that was good, he would buy it.

It sounds like he had a very scientific mind.

Charles Townes: I think that one might say that. He was a lawyer actually. I think there are many similarities between law and science. Investigation, understanding, and so on, logic.

Was there a particular person who inspired you as a child, to take the career direction that you did?

Charles Townes: I don't think of anyone who I would say, that's the person who inspired me. On the other hand, I was very much influenced by my older brother, certainly. He and I went around together, and I tagged along for a while. And I worked with him, we collected together. And we did a lot of things together. So I had a great time with my older brother. It was very stimulating, it was always challenging. He was usually a little better than I was. One reason perhaps I didn't go into biology is because he was so much better than I that I had to pick something different. I did think seriously about biology, but on the other hand, I'm pleased that I went into physics. That attracted me even more.